JPH0314957B2 - - Google Patents

Description

Claim 1: An amphoteric mucilage composition of a cationic starch (CS) with a low degree of substitution and an anionic polymer (AP) with a high degree of substitution as an internal binder is utilized, and this mucilage composition is applied to a slurry containing filler particles. In papermaking processes in which the mucilage composition is added as an aqueous suspension, whereby the mucilage composition is adsorbed as a mucilage coating onto the filler particles, the mucilage coating is then applied to a colloidal solution of polysilicic acid or a polyaluminum-oxy-compound. Partially dehydrated and hardened to a resistant gel coating by addition of a colloidal solution, this addition is based on the weight of CS used, calculated as SiO ₂ or Al ₂ O ₃ A papermaking method characterized in that it is carried out in an amount of less than %.

2. A colloidal solution of polysilicic acid or a colloidal solution of polyaluminum-oxy-compound is added in an amount of 1 to 5%, calculated as SiO ₂ or Al ₂ O ₃ , based on the weight of CS used. 1
Method described.

3 Mucus composition is 0.02 per glucose unit
cationic starch (CS) with a degree of substitution (DS) of ~0.05 quaternary amino groups and carboxymethyl cellulose (CMC) with a DS of 0.5 to 0.9 carboxyl groups per glucose unit;
2. A method according to claim 1, comprising an amount of 1 to 8 parts CMC per 100 parts by weight CS.

4 Mucus composition is 0.02 per glucose unit
Cationic starch with DS of ~0.05 quaternary amino groups and uronic acid polymer (alginate)
1 ~ uronic acid polymer per 100 parts by weight of CS
Claim 1 consisting of an amount of 8 parts, preferably 2 to 3 parts.
Method described.

5. An aqueous filler slurry containing kaolin pigment, talcum pigment, titanium dioxide pigment, chalk pigment and/or limestone pigment contains 10 to 30% of the filler and 2 to 30% of the dry weight of the mucilage composition, based on the weight of water. 4
% and in an amount of 5 to 15% by dry weight of the mucilage composition based on the weight of the filler. The method described in.

6 Polysilicic acid colloidal solution is mainly SiO ₂ /
It consists of an alkali salt of hexasilicic acid obtained by neutralization of water glass with an M ₂ O ratio of about 3.3/1 and an alkali content of about 50%, which polysilicic acid is based on the weight of the dry mucus composition. 6. A process according to claim 1, wherein an amount of 1 to 4%, calculated as _SiO2 , is added to the mucilage-coated filler slurry before or after its mixing with the cellulosic fiber furnish.

7 A colloidal solution of a poly-aluminum-oxy compound has about two of the three Al valences hydrolyzed, while the remainder of the Al valences have the indicating unit formula Al ₄ ( OH) ₈ Ci ₂・SO ₄ (Ci=
The polyaluminum compound is bound alternately to citric acid and a strong inorganic acid according to the weight of the dry mucilage composition used, calculated as Al ₂ O ₃ based on the weight of the dry mucilage composition used. 5% to the mucilage-coated filler slurry before or after its mixing with the cellulosic fiber furnish.
5. The method according to any one of 5.

8 Curing is carried out in two steps, the first step being at a high concentration of the coated filler before mixing with the cellulose fibers, and the second step being at a high concentration of the filler slurry diluted with the cellulose fiber furnish. 8. A method according to any one of claims 1 to 7, which is carried out in.

9. Claims 1 to 8 in which one of the curing steps is carried out with a colloidal solution of polysilicic acid and the other curing step is carried out with a polyaluminum-oxy compound.
The method according to any one of the above.

Description The present invention relates to a papermaking process and is based on the use of novel amphoteric compounds as binders for fillers and second grade fibres. This new amphoteric compound is obtained by the reaction of a low charge density cationic starch with a high charge density linear polyanionic polymer such as carboxymethyl cellulose and polyacrylic acid. This reaction produces complex organized structures that are chemically related to certain biological mucilage polysaccharide structures. This compound itself is an effective and mechanically strong envelope structure around the filler particles and fibers, thereby improving the bonding of the filler particles and fibers in the final paper structure. It can be recognized as an envelope structure. The present invention describes the use of inorganic polymer colloids of strongly ionic character for the ultimate reweaving of the "mucus envelope" into a mechanically strong structure capable of withstanding heavy drainage forces on paper machine wire. It is also based on usage.
The process of the invention can be used in regular papermaking and provides extremely high retention and extremely high paper strength at extremely high filler contents of 30-60% of paper weight.

Cationic starches have been used in the paper industry for a long time, but in small percentages of 0.2-1.0% based on paper weight. According to the present invention, the amount of cationic starch used for paper manufacturing can be increased to 3 to 10% without causing any process problems. Starches containing both cationic and anionic groups were initially proposed as paper binders, including mixtures of cationic and anionic starches. However, these proposed schemes are limited to low charge density anionic starches,
In other words, bS (degree of substitution) of commercially available cationic starch
It concerns anionic starches with a DS of 0.01-0.10, comparable to 0.015-0.050. Mixtures of coacervate cationic and anionic polymers as additives to paper have been proposed by Economou (USP No. 3790514) and Voigt (USP No. 4066495). In addition, a mixture of cationic starch and a large amount of alginate was used by W. Jones, GB No. 1 to improve the acid resistance of the chalk in the paper.
1425114). According to our studies, the proposed coacervate combination would only give an inferior paper compared to the inventive combination. . These publications never indicate any curing of amphoteric mixtures by colloidal inorganic polymers.

The inventors have determined that the highest possible molecular weight (100000~
500000) and 0.025 to 0.050, preferably 0.030 to
Best results have been obtained with a cationic starch (CS) with a DS of 0.035 [corresponding to approximately 6000 EW (equivalents)].

Registered Trademark Carboxymethyl Cellulose (CMC)
Also available in various MW and DS. Their DS is generally very high, from 0.40 to
We have found that a high DS of between 0.60 and 0.90, preferably between 0.70 and 0.80 (corresponding to an EW of about 300) is suitable for the present invention. Here, a DS of less than 0.10 is referred to as "low" (low charge density), and a DS of more than 0.50 is referred to as "high". moreover,
A medium MW CMC of 50,000 to 300,000, corresponding to a Bruckfield viscosity of 20 to 300 cps for a 2% solution, is preferred, even though CMCs outside these limits can be used.

2 to 2 of a mixture of equivalent amounts of CS (EW6000) and CMC (EW300) (i.e. 5 parts CMC per 100 parts CS)
When preparing a 3% aqueous solution, a somewhat cloudy, low viscosity solution is obtained. If left standing, the CS-CMC precipitate will gradually separate. Although such products can be used in the present invention, they are not the most efficient products obtainable. For the most efficient product,
As mentioned above, only about half the amount of CMC should be used, i.e. 2 to 3 parts of CMC for every 100 parts of CS, and preferably this should be in water in which the CMC should swell and "dissolve". CMC
should be pre-dissolved. Direct steam injection for a long period of time, which is technically recommended, to obtain a “molecular solution free of structural aggregates”
CS dissolution methods should be avoided in practice. As mentioned above, the most effective structure of the CS-CMC reaction product is obtained when the reaction product is formed already while the starch granules are swelling and dissolving. It is technically advantageous to use a dry mixture of CS and 2 to 3 parts of CMC as Na salt. When mixed with cold water,
The CMC component dissolves without creating CMC clumps. Otherwise, a bunch of CMC will cause trouble. CS
Under the production of special structures with CMC, 50-60
Begins to swell at ℃. 90-100℃ of the generated structure
Cooking must continue for 10 minutes, but contrary to pure CS, the character of CS does not change during continued cooking. The resulting solution is somewhat cloudy and has a much lower viscosity than the same concentration of CS alone. This solution can be made with a CS concentration of 2-6%.

The optimal ratio of CS to CMC or other anionic polymer is not related to the equivalence point or to a fixed relationship of anion to cation ratio. the important thing is,
Organization of anionic and cationic regions inside the resulting mucus structure
cationic areas). This optimum ratio must be determined by testing for each CS-anionic polymer combination. DS=1.0
For neutral alginic acid with DS = 0.7 it is the same as CMC, ie 2-3 parts per 100 parts of CS.
For polyacrylic acid with DS = 1.0 (but with smaller units than glucose), the optimal weight ratio is
Approximately 1.5 copies per 100 copies of CS. If the polyacid content is too low (CMC/CS = less than 0.5/100), the final mucilage structure containing the filler is mechanically too weak and insufficient for the final binding of the pigment into the paper. If the polyacid content is too high, the structure resists incorporation with fillers.
Polyacid/CS ratios greater than 10/100 are of little use, with practical limits being 1 to 8/100CS.

As mentioned above, alginic acid and polyacrylic acid from seaweed can be used as reactants with CS, but CMC currently appears to be the most economical reactant. Commercially available water glass (ratio
3.3/1) corresponds to the disodium salt of linear tri- and tetrasilicic acids. If water glass, further polymerized as the disodium salt of pentasilicate, is used as the first reactant with CS, an increasingly rigid gel structure with high and complex viscosities is obtained. Therefore, for the initial preparation of the mucus composition, up to
A silicic acid oligomer of 4SiO ₂ should be used. For the final curing of the slime structure into a resistant gel, higher three-dimensional polymers (penta- and hexasilicates) should be used, exceeding 4 SiO ₂ per mole. A suitable method of utilizing cheap water glass for the present invention is to divide its use into two steps and combine it with CMC. in this case,
100 parts of CS with 1-2 parts of SiO ₂ oligomer or
Swell with CMC. 1 for CS at low temperatures
An amount corresponding to ˜4% of diluted further polymerized water glass, for example hexasilicic acid, is added. See Example 5 for hexasilicic acid. This latter addition can also be carried out together with the addition of the filler suspension, or more conveniently afterwards.

2 parts CMC (DS0.7, MW150000) and 100 parts
The chemical structure obtained by reaction with CS (DS0.03, MW300000) contains 20 to 30 one central CMC unit.
It must resemble an "ionically bound coacervate" surrounded by individual cationic starch units. Although such a structure should theoretically give a high viscosity, in reality the viscosity of the resulting structure is rather low, indicating that the coacervate is more concentrated in larger, denser, harder structures. , indicating that it is assembled into the original, but swollen, CS grains, probably with some CMC enrichment on the surface. Swollen starch grains (potato starch) have a particle size of approximately 100 microns. The primary structure obtained by dissolving CS in CMC solution has some further interesting properties.

1 Contrary to pure CS, this structure exhibits a stable viscosity during prolonged cooking, and this viscosity is surprisingly low even after swelling is complete. The aqueous phase containing the primary structure does not contain dissolved starch when this aqueous phase is separated and analyzed. The product obtained is therefore not a true solution, but a suspension of substantially insoluble mucilage structures, coacervates of anionic-cationic polyelectrolytes.

2 The water of suspension and the mucus composition, ie, the suspended particles, generally exhibit a PH difference that is maintained for several days until the structure loses viscosity and breaks down. The root of this difference lies in the fact that CMC or other polyacids used are added as slightly alkaline salts (PH 7-9), whereas CS is generally neutral (PH 6-7), whereas the It is surprising that these primary structures have a "membrane-effect" that persists for a very long time. PH test paper strips
When immersed in CS-CMC solution, exhibits an external PH of 8-9. Squeezing or rubbing between the fingers the pieces to which the mucus composition is attached reduces the pH to 7, which is associated with structure failure. Thus, the structure is transient and unstable.

3. Contacting the reaction product of CS and CMC (or other polyacids) with a slurry of filler (such as cations or chalk) reorganizes the mucus structure, while simultaneously reorganizing the mucus structure into filler particles. Combine with. This reorganization results in a new secondary structure of filler particles finely enclosed by a slimy envelope of globular droplets. This reorganization is accompanied by a strong viscosity increase and equalization of the PH gradient. The mucus droplets (secondary structures) surrounding the filler readily assemble and separate from the outer water, which does not yet contain substantial amounts of dissolved CS or CMC. Mixing of the primary structure and filler slurry can be done cold or with the CS-CMC product still hot. The PH is not critical and can vary between 5 and 9 depending on the filler (kaolin-acidic and chalk-alkaline). A suitable CS-CMC:filler ratio is 10%, but the amount of CS-CMC binder can vary between 2 and 20% of the weight of the filler. The economical optimum is 5-15%.
When no or only small amounts of filler are used, the addition of 1-8% CS-CMC to the weight of the dry furnish can be used to compensate for the lack of strength associated with secondary fibers. Useful.
The concentration of the filler suspension can vary between 10 and 30%, and the concentration of the CS-CMC compound can vary between 2 and 4%. Concentrations higher than this can result in agglomeration of the filler and poor contact with the CS-CMC binder. Such clumps give a "dotted", dusty paper and reduce surface strength. Lower densities can be used, but the strength of the final paper will be lower. Thus, if secondary structures are formed at high dilutions,
This secondary structure will also be "diluted" and weakened. This secondary structure appears to consist of filler particles finely encapsulated within droplets of CS-CMC mucus. The structural block of this mucus consists of a central anionic CMC unit (or other polyacid used) surrounded by 20-30 CS molecules, and an ionic bond between the CS and CMC. It must be a coacervate held together by force and extensively hydrated. The peripheral S-branches of this aggregate are bound to the slightly anionic filler particles by ionic bonds and cover the filler particles with an envelope. The filler particles are 1 to 10 microns in size, while the mucus unit blocks are less than 1 micron and can be bound together with other blocks by other CMC units into giant mucus molecules that span the entire droplet. Must be. The surprising properties of this secondary structure are that the droplets can assemble into large dough lumps in a reversible manner, can be separated by sieving, and have good formation. It can even be extensively dried before being redispersed into a useful furnish with properties.

Simple ionic bonds in polyelectrolytes are neither strong nor stable. In biological mucopolysaccharides, stability is obtained with glucose-amine and glucose-acid DS = 1 and is often enhanced by protein crosslinks. Therefore, the secondary structure is not stable and gradually reorganizes into a lower viscosity structure and finally disappears and the filler particles are redispersed into the external aqueous phase. The secondary structure is also transient and must be used within 24-48 hours after preparation. In particular, chalk-filled structures are sensitive to aging, probably due to the gradual formation of Ca ions that react with the MC, thereby weakening the CS-CMC bond. The primary CS-CMC mucus without filler is also transient.
This primary CS-CMC mucilage has the highest absorption capacity for fillers when freshly prepared, but is still useful after 24-48 hours.

The role of CMC (or other polyacids) can be illustrated as follows. The cationic-anionic starch mixture has a high DS in the anionic portion;
And it does not give these characteristics unless it is decomposed into short linear molecules.

1 CMC (or other polyacid) combines with CS,
A large, hydrated but virtually insoluble mucus coacervate results.

2 CMC (or other polyacids) contributes to the high ionic and surface activity of these coacervates, which allows them to encapsulate fillers effectively and in a highly dispersed manner.

3 CMC (or other polyacids) also contribute to the improved mechanical resistance of the mucus composition when the mucus structure is reorganized into a gel in the next step of the process.

4 Additionally, CMC (or other polyacids) binds filler more effectively than any starch combination in the final paper.

Although the secondary structures of encapsulated fillers in droplets of CS-CMC mucus may appear stable in laboratory tests, they are often exposed to the wire mesh of rapidly running paper machines. It is not mechanically strong enough to withstand strong drainage forces on the wire, and in any case is not strong enough to give the desired 90-95% filler retention in one pass over the wire mesh. Therefore, 2
It is essential to reorganize or "harden" the secondary structure into a tertiary, more resistant gel structure. This is done by a synerese reaction (dehydration) obtained by adding small amounts of colloidal, mainly inorganic polymers with a very high surface charge. Such inorganic polymers of anionic nature are polysilicic acids having 5 to 50 SiO ₂ units per molecule, although certain polyaluminum compounds are examples of suitable cationic polymers. Furthermore, citric acid-sulfuric acid-polyaluminium (polyaluminium-citrate-sulfate) corresponding to the formula Al ₄ (OH) ₈ Ci ₂ ²⁺・SO ₄ ^2- (Ci = citric acid equivalent)
The complex compounds appear to be amphoteric polymers with both anionic and cationic surface charges and are very effective. Reorganization from primary to secondary structures is achieved by coarse filler particles (1-10 microns) with rather weak surface charges, whereas reorganization from secondary to tertiary structures are colloidal particles with extremely high surface charges (1 to 10
(millimicrons). The main reaction in both cases is the ionic binding of glucose chains (starch chains) to the particle surface. However, the second reaction is significantly more powerful and results in the production of denser, dehydrated mucus or gel droplets that have an increased tendency for irreversible aggregation and can withstand drainage forces.

The second reaction with the colloidal inorganic polymer can be carried out before mixing the cellulose fibers into the furnish. This reaction can also be carried out after mixing the cellulose fibers, but in this case it is permissible to have a reaction time of 10 to 60 seconds before returning to the paper machine and diluting with water. The syneresis reaction of the secondary structure to the tertiary gel structure is rapid but not spontaneous. This second reaction can also be divided into two steps, with the first step being performed before mixing with the cellulose fibers and the second step being performed after mixing. The latter method is advisable if groundwood fibers are to be used, since the wood fibers are contaminated with anionic and lipid compounds that interfere with the reaction. When the reaction is divided into two steps, it is preferable to use a polyaluminum compound in the first step and a polysilicate compound in the second step, or vice versa.

The amount required for curing of the inorganic colloidal polymer is less than 10% for starch, often 1-5% and 0.1-0.5% for filler at a standard starch/filler ratio of 1/10. If the secondary structure is well developed and not aged, and if aided hardening is effective, e.g. with hexasilicic acid, in many cases
For fillers 0.1-0.3% and for starches 1-3% are sufficient. The % is calculated here as SiO ₂ or Al ₂ O ₃ . If the secondary structure is weakened or poisoned, the first cure can be performed with a polyAl complex and the second cure with a silicic acid polymer.

The fiber component of the furnish may consist of kraft sulfate or sulfite fibers, preferably refined to a somewhat higher degree than normally used for the paper type involved. It can also be made of ground wood fibers. According to the invention, very high filler contents of 30-60% of paper weight can be used without substantial loss of strength and other important properties. This is demonstrated in the examples below.

It will be obvious that the invention may be practiced otherwise than as optimally described above. for example,
The cationic starch can be allowed to swell in pure water to some extent and without cooking for a long time, and then the anionic polyacid can be added. Although such methods are suitable for laboratory use, they are difficult to keep within reproducibility limits on an industrial scale with large volumes. Other fillers can be used, such as talc, titanium dioxide, etc., but kaolin and chalk are the most common and most economical. The combination of kaolin and chalk has the advantage of keeping the furnish PH around 7, where hardening action is most effective.

Rosin sizing and other sizing, such as sizing with Aquapel (registered trademark of Aquapel, a type of rosin sizing) for water resistance, are performed by mixing mucilage-enveloped fillers with the fibrous furnish. Chemicals added to the furnish do not adversely affect the process of the invention.
Again, starch-polyacid-filler 3 in the absence of other anionic, cationic and lipid contaminants.
It is advantageous to allow the formation of secondary structures.

Although cationized starches from various sources such as corn, tapioca, wheat, etc. can be used, potato starch is preferred, at least in Europe, due to its low price and suitable starch grain type. Polyacids other than carboxylic acids and silicic acids, such as synthetic sulfonic acids and phosphoric acids (but linear), and combinations of various acids can also be used.

Example 1 20 g of chalk with an average particle size of 4 microns was made into a 25% slurry with water. Furthermore, a 2% concentration amphoteric mucus dispersion was prepared by the method described below. 2 g of high viscosity cationic starch (CS) was added to 0.05 g of CMC (i.e. CS100
2.5 parts per part of CMC) was dissolved in cold water (100 ml). This cationic starch [Perfectamyl PW] is
The DS was 0.033, but the CMC product [Hercules Corp. product, 7LF] had a DS of 0.033.
It had a low to medium molecular weight of 0.70. This is a very pure product (food grade) that the inventors used in laboratory tests to avoid contaminants. When the mixture was allowed to swell with gentle stirring and digested at 95° C. for 10 minutes, a slightly cloudy, low viscosity suspension was obtained.

Thus, this amphoteric mucilage dispersion was added to the chalk slurry while hot in an amount corresponding to 10% CS and 0.25% CMC based on the chalk weight. The mixture became a finely aggregated structure, with the mucilage-like composition enclosing the filler particles. After 10 minutes, a solution of hexasilicic acid was added in an amount corresponding to 3% SiO ₂ based on the weight of CS (0.3% based on the weight of chalk). The aggregates turned into coarse 1-3 mm chunks, but the aqueous phase became completely transparent. Hexasilicic acid is commercially available water glass (
3.3) was diluted to make a solution containing 2% SiO ₂ , and then half of the alkali content was neutralized with sulfuric acid, and then siloxane polymerization was allowed to proceed for 60 minutes before use.

Cellulose (bleached kraft, 60% hardwood, 40% softwood, refined to 30°SR) 20
g was suspended in turmix and mixed with 0.5% Aquapel.(R) based on the weight of cellulose. The cured starch-mucilage composition was then added to the cellulose with vigorous stirring. In this case, the final furnish had a composition corresponding to 47.2% cellulose, 47.2% chalk, 5.12% CS-CMC, _0.13 % SiO2, and 0.25% Aquapel (emulsion).

Divide this paper stock into 10 parts and weigh 100g/m ²
I created a handsheet for Grammage. The return water was conditioned and completely clear. The weight of the 10 handsheets was 42.20 g compared to the furnish dry solids weight of 42.12 g.
Therefore, the yield was 100% and the paper formation was very good.

The properties of the paper were as follows.

Tensile index: 33 Nm/g Elongation: 2.9% Wax value: 15 Opacity: 96% Brightness: 77% Example 2 The same test as in Example 1 was conducted. However, 2.5%
1.5% polyacrylic acid (Na salt) instead of CMC
was used. The yield value was also close to 100% in this case. The percentages of CMC and polyacrylic acid are based on the weight of cationic starch. The properties of paper are determined by Dennison's tensile index.
It had a wax value of 29 Nm/g and a wax value of 13.

Example 3 The same test as in Example 1 was conducted. However, CMC2.5
%, alginic acid (DP=300) 2.5% was used. In this case, a cellulose furnish with Aquapel was mixed into the filler-mucilage-slurry.
The resulting aggregates are extremely fine (no coarse lumps);
Immediately before making the handsheet, add 1/3 of the acid content with NaOH.
A polyaluminum oxysulfate solution prepared by neutralizing
It was added in an amount equivalent to 0.2% Al ₂ O ₃ (2% based on starch). The aggregates obtained were extremely fine and the rehydrated water was completely transparent. Paper formation was excellent and the calculated filler yield was 96%.

Tensile index: 32Nm/g Wax value: 15 Example 4 English grade E with average particle size 2-5μ
20g of kaolin (dry) from E) was made into a 25% slurry with water. To this slurry, the same ampholytes as in Example 1 were added.
CS-CMC composition (CMC/CS=2.5/100),
It was added in an amount equivalent to 10.25% based on kaolin.
1.0 on starch basis after encapsulation of filler with mucilage
% (0.1% based on kaolin) of SiO ₂ and added as water glass.

The same cellulose as in Example 1 was used, but Aquapel was not used and the filler/cellulose ratio was 1/1. After mixing the kaolin suspension with the fiber furnish under moderate stirring (fine aggregates do not require vigorous stirring due to uniform distribution), 33% neutralized polyaluminum oxysulfate solution was added in an amount corresponding to 0.2% Al ₂ O ₃ based on kaolin. Again, 10 hand sheets with a gram age of 100 g/m ² were prepared. The calculated yield was 98%. The returning water was almost very slightly cloudy. To reach this yield, the aggregate had to be improved by adjusting the PH of the furnish to 5.5 after Al addition. This handsheet exhibited the following properties.

Tensile index 28Nm/g Elongation 2.2% Wax value 11 Opacity 98% Brightness 75% Example 5 20g (dry weight) of grade E (2-5 microns) kaolin was made into a slurry with 60g of water, and the kaolin weight 0.2g corresponding to 0.25% _SiO2 for
of normal water glass was added. Water 50 to which another 0.2 g of water glass (SiO ₂ /Na ₂ O = 3.3) is added
After slurrying 2 g of CS (DS = 0.035) at g,
Heat and evaporate for 10 minutes. This hot swollen starch suspension was added to the kaolin slurry to produce a highly viscous slurry of mucus droplets encapsulating kaolin. The SiO ₂ /CS ratio of the mucilage-filler structure produced was 5/100. After 30 minutes, 2 more for every 100CS
of SiO ₂ was added, but henceforth it was added as “hexasilicic acid” (50% of the alkali water glass neutralized with sulfuric acid for 60 minutes in a dilute solution). This resulted in separation of the mucus-filler-aggregate, which transformed into a harder gel aggregate separated from the clear aqueous phase.

To this assembled gel structure was added 20 g cellulose furnish (same as in Example 1, but using sulfate rosin instead of Aquapel). Under effective stirring, disperse the aggregate and prepare the alkaline furnish with polyaluminum sulfate, furnish pH 5.8.
After neutralization (1/3 neutralization), a paper sheet was created. The yield was 98%, and paper with 50% filler was produced. The tensile index was 29 Nm/g and the Dennison wax pick up was 13.

Example 6 This example is to demonstrate the effect of an amphoteric CS-CMC binder on cellulose paper in the absence of filler. First, a standard paper was made from the cellulose of Example 1 without the addition of filler or starch binder. The yield was in any case more than 97% and the pure cellulose paper showed a tensile index of 57 Nm/g and a wax number of only 13.

Second, without fillers, but with a cellulose basis of 5
% amphoteric CS-CMC composition was used to produce cellulose paper. The amphoteric composition was the same as in Example 1 (CMC/CS=2.5/100). Before making the handsheets, the cellulose-starch complete stock was enriched with 0.15% Al ₂ O ₃ calculated on the dry weight of cellulose.
, polyaluminum oxysulfate (33%
It was added as a neutralizing agent. In this case the yield is 100
% and contained starch and curing compounds. This paper has a tensile index of 62Nm/g and
It showed 23 remarkable wax values. This example shows that when an amphoteric CS-CMC binder is applied to a cellulose-only furnish,
This shows that the most significant effect is on the

Example 7 The following tests were conducted on an experimental paper machine. A 25% slurry was made by dispersing 50 kg of chalk (4 microns) in water. Separately, Swedish SCA-grade CMC called FF20 has a Burdskfield viscosity of 20 cps at 2% concentration.
(DS0.7) CS in water 100 containing 0.12Kg
(DS0.035) 5 kg of slurry was prepared. After cooking for 10 minutes, the hot CS-CMC product was diluted to 2.5% and added to the chalk-filler slurry to form a filler-mucilage slurry having 10% CS to chalk and 2.4 parts CMC per 100 parts CS. I got it.

This filler-mucilage slurry was then mixed with 50 Kg of cellulose (50% hardwood, 50% softwood, refined to 30° SR) at a consistency of 4% and containing 0.4% Aquapel hydrophobic emulsion. . This blended furnish exhibited a very fine agglomeration of mucilage-filler droplets along with fibers. To this mixed furnish, then CS
1% Al ₂ O ₃ by weight was added to a polyaluminum citrate sulfate complex solution (complex
It was added as a polyaluminium-citrate-sulfate-solution). This complex is made by dissolving 1 mole of aluminum sulfate in 2 parts of water, adding 1/3 mole of citric acid, and finally dissolving 5/6 of aluminum sulfate in sulfuric acid.
It was prepared by adding 5N NaOH equivalent to neutralize over 3 hours. After this addition, the furnish further aggregated and a finished clear aqueous phase was obtained. The furnish was left overnight. The next day, the experimental paper machine was loaded with the addition of 3% SiO ₂ based on the CS weight as hexasilicic acid (disodium salt). A solution of hexasilicate is prepared by precipitating the washed silicic acid into a water glass with SiO ₂ /
It was produced by dissolving the Na ₂ O ratio = 6.0. Hexasilicic acid was reacted with the furnish for 40 seconds and then diluted with reconstituted water.

The furnish drains quickly on a wire mesh, and the paper machine
Worked without any problems and interruptions. The paper dried extremely quickly and filler retention was estimated at 91%.

Gram age 75g/m ² Density 780Kg/m ³ Tensile index √ 33kNm/Kg Rupture index 2.0MN/Kg Tear index √ 5.5Nm ² /Kg Elongation at break √ 2.5% Denison wax both sides/2 16 Gurley 13s. Kotsub (Cobb) 15g/m ² Unger bs/2 27g/m ² Brightness bs/s 77% Opacity 92% Filler content 45%